Shuttle threading block



May 10, 1955 J. M. TUTEN SHUTTLE THREADING BLOCK Filed Feb. 11, 1953FIJI 15 324 f izfi" A TTORNE Y 39 INVENTOR. JAMES M. TUTE N UnitedStates Patent 2,707,975 SHUTTLE THREADIN G BLOCK James M. Tuten,Greenville, S. C., assignor to Draper Corporation, Hopedale, Mass., acorporation of Maine Application February 11, 1953, Serial No. 336,216 4Claims. (Cl. 139-223) .This invention pertains to improvements inthreading blocks for loom shuttles.

It is a general object of the invention to devise a threading block forloom shuttles which shall be easily molded from a non-ductile metal suchas cast iron and then formed into a completed article by simple andeasily accomplished machining operations.

It is a further object to devise a shuttle threading block which shallserve effectively to shed all kinds of loops occasioned by the unusualbehavior of the filling as it comes from the bobbin, including so-calledback loops and double front loops.

It is another object of the invention to devise a threading block ofvery rugged design and having an integrally cast scroll which is ofuniform cross-secti0n throughout its length and which shall be easilythreaded, reasonably effective against unthreading and strong enough toresist the damaging tendencies to which it may be subjected by a trappedbobbin.

Other objects will become apparent from the following disclosure.

In loom shuttles, especially the type used in automatic looms, thefilling is theaded through a threading block, sometimes referred to as ashuttle eye, and which must serve to control the filling as it is drawnfrom the bobbin and delivered by the shuttle during Weaving.

In some shuttles, blocks are used which are integrally cast to comprisethe body, horn, side eye notch, scroll and, in fact, all parts except asteel pin or pins which are inserted in the finished block after it hasbeen machined. Examples of such eyes are evident in U. S. Patents2,336,937 and 2,470,064. While these function with a degree of success,they are not adapted to shed all kinds of undesirably encountered loopsand in the case of a scroll with a continuous taper as in the formerpatent, problems of manufacture are encountered which it is desired toavoid.

According to the instant invention, a threading block is so devised asto be cast from non-ductile material and machined by simple, straightforward metal cutting operations to provide a finished block having alongitudinal thread passage defined in part by an integrally cast scrollof substantially uniform cross section to avoid the added productiondifficulties attendant upon machining a corresponding part with acontinuous taper. The said scroll is inclined at an angle to the path ofthe filling through the block and toward the horn end of the same.

A thread entrance slot is formed which is preferably of uniform widthand cut on an arc the radius of which is centered at the center of thelongitudinal thread channel, and which terminates at the approximatevertical center plane of that channel, and a second slot cut from thechannel downwardly to enter the arcuate slot at its terminus.

This scroll is formed at an angle to the horizontal path of the fillingthrough the block by casting and/or machining as will be described. Theangle is such as to permit all types of unintended but unavoidable loopsto be shed, that is, to slip off the scroll rather than catching orhanging thereon. These loops also slip from the scroll as herein formedwithout developing appreciable extra tension on the filling which, ofcourse, would easily break if that were done.

The details of the block, the method of manufacture and its operationwill be described in detail in the following description which refers tothe accompanying figures of drawing wherein:

Fig. 1 is a plan view of a shuttle to which a block according to theinvention has been applied.

Fig. 2 is an elevation of the shuttle of Fig. 1.

Figs. 3-8 are end views of the threading block showing progressive stepsin its manufacture.

Fig. 9 is a view of the completed block as seen from the horn end.

Fig. 10 is a sectional view showing further details of the scroll whichforms a part of the block.

Now referring to Figs. 1 and 2, a shuttle 20 of conventional designcarrying a bobbin 21 with filling F Wound thereon is provided at itsfront end with a suitable recess 22 within which is retained a threadingblock generally denoted by numeral 23. This block is cast from anonductile material such as a good grade of cast iron and comprises abody portion 24, Fig. 9, for example, a horn 25 having a lip 26, anapron 27 extending toward the front side of the shuttle, and a scroll 28defining in part a longitudinal thread channel 29. The thread or fillingis threaded into channel 29 through slots 30 and 31, the first followingan arc concentric with the channel and the second being cut verticallyfrom the channel to the terminal part of the arcuate slot.

As seen in Figs. 1 and 2, the forward end of the shuttle is grooved at32 and 33 to assist in threading the filling beneath the scroll and alsodown under the horn 25 at the first pick after replenishment whereuponthe filling will pass through the longitudinal thread channel and underlip 26. At the following or return pick the filling will be cammed underhorn 25 and apron 27 to enter side eye E in the shuttle, at the sametime being snapped under point 34 and and into upwardly directed notch35, Fig. 10. A pin 36 of hardened steel is inserted through appropriateapertures in the block and is of such height as to hold the filling,when taut, at about the level of the bottom of the longitudinal threadchannel. When threaded automatically, the filling snaps under the scrolland then runs through the thread channel 29 being elevated by pin 36 soit is virtually impossible for it to become unthreaded.

The scrol 28 defines one side or about of the circumference of thechannel 29 and is inclined as more clearly shown in Fig. 10 at an angleof approximately 45 to the horizontal or path of the filling at thatlocation. That inclines the back face 37 of the scroll and of the blockadjacent the scroll so that a filling loop resulting from improperrelease of the filling from the bobbin will be shed or permitted to slipover that part of the block and scroll with no tendency to catch. With amuch steeper angle of face at this point such loops are not shed and, ofcourse, filling breakage results. After shedding, the fillingimmediately rethreads itself.

The front face 38 is exactly parallel to face 37 insofar as is possiblein commercial-production. This front face is formed during molding whilethe face 37 is preferably produced by machining.

Now having described the general characteristics of the block, a briefdescription of the machine operations performed thereon will be given.After the casting, Fig. 3, has been snagged and preferably annealed, thelongitudinal thread channel 29 is formed by drilling, Fig. 4. This holeis drilled substantially on the horizon- 3 tal, but possibly at a slightdownward angle toward the front or horn end of the block.

The recess at the rear of the block is then cut by end milling. Fig. 5,so that the face 37 will be parallel to face 33, Fig. 10. According topreferred practice the cut is made so face 37 will be inclined at about45 to the horizontal.

The arcuate slot 3%, Fig. 6, is not started as such, but a straight,vertical cut is first made down to the horizontal center plane of thehole 29. This cut is parallel with the back wall 24 and facilitates thestart of the arcuate cut which, of course, is more difficult and moredelicately accomplished.

A band saw is preferably utilized to make the arcuate cut, and at thattime the block is located on a jig pin passing into the hole for thelongitudinal thread passage. The block is turned on this jig pin as acenter so that the saw must cut slot 3%) concentrically disposed to thehole. This actually forms the scroll 28 which will thus be bounded byconcentric cylindrical surraces and parallel end faces; thus it willhave a cross-section of substantially uniform area as desired. Thearcuate cut may be carried slightly past the vertical center plane ofthe longitudinal thread channel.

it remains to interconnect the hole 29 and arcuate slot 30, Fig. 7, andthat may be done by use of a saw or a broach. The block is at that timeremoved from the pin and held rigidly in a fixture while the cut is madefrom the hole downwardly into the slot. The cut is evenly spaced toeither side of the vertical center plane of the channel 29 or slightlytoward the back wall.

The hole for pin 36 is drilled and the pin may be inserted at anyconvenient time.

The entire block is sand blasted to smooth it, and sharp corners whichmight harm a thread, interfere with its threading or the shedding of anundesired but unavoidable loop in the filling are all rounded in anyconvenient manner.

At Fig. 3 the finished block is shown after all operations have beenperformed including insertion of the pin 36 and drilling of a hole 39,Figs. 9 and 10, through which a retaining bolt, l, is passed.

in u this blQCrZ will thread easily and has a maximum ct res. lance tounthreading especially when pin 36 is placed so its top edge is abouteven with the horizontal plane of the bottom of channel 29, or slightlyhigher.

The very solid and rugged construction makes it virtu'clly impossiblefor a trapped bobbin to damage the bloclt in any way. The smoothsurfaces and the angular disposal of the scroll facilitate the sheddingof all types of loops as above mentioned, this being accomplishedwithout subjecting the filling to added tension such as might cause itto break.

While cast iron has been mentioned as a preferred material, it is to beunderstood that any metal normally classified as non-ductile may beused. The order of machining operations and the manner of performingthem may be varied so long as the ultimate result is the formation of athreading block as described.

While one embodiment of the invention has been disclosed, it is to beunderstood that the inventive concept may be carried out in a number ofways. This invention is, therefore, not to be limited to the precisedetails described, but is intended to embrace all variations andmodifications thereof falling within the spirit of the invention and thescope of the claims.

I claim:

1. A threading block for loom shuttles comprised as a non-ductile metalcasting and having means defining a longitudinal thread channel ofcircular cross-section, a

side eye recess, a horn with a thread confining lip, said means definingthe longitudinal thread channel including a scroll integral with thecast block, said scroll being of substantially uniform cross-section andinclined at an angle toward the horn end of the block, and meansdefining thread entrance slots leading to the longitudinal threadchannel, one said slot leading downwardly and then arcuately on a radiusconcentric with the longitudinal thread channel and a second slotleading from the terminal portion of said arcuate slot vertically towardthe center of the longitudinal thread channel.

2. A threading block for loom shuttles comprised as a non-ductile metalcasting and having means defining a longitudinal thread channel ofcircular cross-section. a side eye recess and a horn with a threadconfining lip, said means dc 1c he longitudinal thread channel ineludinga scroll integral with the cast block, said scroll h 3g of substantiallyuniform cross-section and inclined at an angle of substantially 45 tothe longitudinal thread channel and toward the horn end of the block,and means defining thread entrance slots leading to the longitudinalthread channel, one said slot leading downwardly and then arcuately on aradius concentric with the longitudinal thread channel and a second slotleading from the terminal portion of said arcuate slot vertically towardthe center of the longitudinal thread channel.

3. A. threading block for loom shuttles comprised as a nonductile metalcasting and having means defining a longitudinal thread channel ofcircular cross-section, a side eye recess, and a horn with a threadconfining lip, said means defining the longitudinal thread channelincluding a scroll integral with the cast block, said scroll being ofsubstantially uniform cross-section and inclined at an angle toward thehorn end of the block, the front and rear transverse faces of saidscroll being parallel and the rear said face forming with adjacentperpendicular bounding walls, an indentation at the thread entranceportion of the block for facilitating entry of the thread and sheddingof a back loop of filling, and means defining thread entrance slotsleading to the longitudinal thread channel, one said slot leadingdownwardly and then arcuately on a radius concentric with thelongitudinal thread channel and a second slot leading from the terminalportion of said arcuate slot vertically toward the center of thelongitudinal thread channel.

4. A threading block for loom shuttles comprised as a non-ductile metalcasting and having means defining a longitudinal thread channel ofcircular cross-section, a

' side eye recess, and a horn with a thread confining lip,

said means defining the longitudinal thread channel including a scrollintegral with the east block, said scroll being of substantially uniformcross-section and inclined at an angle toward the horn end of the block,and means i defining thread entrance slots leading to the longitudinalthread channel, one said slot leading downwardly and then arcuately on aradius concentric with the longitudinal thread channel and a second slotleading from the terminal portion of said arcuate slot vertically towardthe center of the longitudinal thread channel, and a pin disposedtransversely of the block and forwardly of the scroll, said pin being ata height to hold filling threaded through the block at substantially thelevel of the lowest part of the longitudinal thread channel.

References Cited in the file of this patent

